Question

A typical silo on a farm has many metal bands wrapped around its perimeter for support as shown in Figure CQ14.19. Why the spacing between is successive bands smaller for the lower portions of the silo on the left, and why are double bands used at lower portions of the silo on the right?

Short answer

The metal bands are placed closer, or doubled, at lower portions to provide more force to balance the force from the greater pressure.

Step-by-step solution

Pascal’s law

Pascal’s law states that when pressure is applied to an enclosed fluid, the pressure is transmitted undiminished to every point in the fluid and to every point on the walls of the container.

The pressure in a fluid at rest varies with depth h in the fluid according to the expression

$P=P_0+\rho gh$

Where$P_0$ is the pressure atdata-custom-editor="chemistry" $h=0$ and$\rho$ is the density of the fluid, assumed uniform.

Explain the reasoning

The stored corn in the silo acts as a fluid: the greater the depth, the greater the pressure on the sides of the silo. The metal bands are placed closer, or doubled, at lower portions to provide more force to balance the force from the greater pressure.